The Oregon National Primate Research Center (ONPRC), Oregon Health & Science University (OHSU) proposes to continue a U54 Contraceptive Development Research Center that targets the discovery and development of novel contraceptive agents that prevent one or more periovulatory events in adult, female primates during the menstrual cycle. Three research projects and one animal core will utilize Old World (macaque) monkeys to generate new information and proof-of-concept regarding potential modalities for preventing oocyte fertilization, and hence fertility, in women. Project I, Control of Oocyte Maturation will address the hypothesis that novel follicle (granulosa) cell- and oocyte-derived proteins control nuclear and cytoplasmic maturation of the oocyte, and can be exploited to prevent timely egg maturation and fertility during the menstrual cycle. Project II, Control of Follicle Rupture and Cumulus-Oocyte Activities will test whether specific antagonists of select granulosa- or oocyte derived proteins disrupt cumulus-oocyte expansion or ovulation, and hence egg release and fertility during the menstrual cycle. Project III, Control of Gamete Transport and Fertilization will investigate reversible and nonreversible methods to locally prevent sperm and oocyte transport in the reproductive tract, and hence fertilization and fertility in female macaques. Based on progress in the prior grant interval and continued basic discovery and elucidation of drug action, promising agents will be tested in the Nonhuman Primate Contraceptive Core for contraceptive efficacy, reversibility and side effects. Ongoing collaboration with colleagues at the University of Minnesota and Bayer Pharma AG (formerly Schering AG), Berlin will facilitate drug discovery, nonhuman primate testing, and ultimately early (Phase I) clinical trials. The Administrative Core will foster intra- and inter-center cooperation in contraceptive research, and liaison with NICHD, CRB project officers. The synergy between reproductive scientists and clinical researchers at ONPRC, OHSU, combined with active collaborations with colleagues in universities and pharmaceutical companies, provides a valuable opportunity to promote translational research in primates that's most relevant to developing novel, ovary/tract-based contraceptives for women.